A person may interact with image-based media in a variety of different ways. For example, one common way for a person to convey information to others is by interacting with images (e.g., slides of a slideshow presentation) that are presented on a display. In some cases, the images may be presented by a computer-controlled projection system that includes a computer that generates image data and a projector that projects the image data onto a projection screen. A person may interact with the projected images by pointing to notable areas of the projected images with a finger, laser pointer, or some other pointing device or instrument.
During a presentation, a person's interactions with the presented images augments a presentation with additional information. For example, by providing additional context and meaning spoken words together with gestures pointing out particular areas of interest in the presented images expand the total information conveyed beyond the information that is summarized in the presented images. This additional information may be captured in video and audio recordings of the person's interactions with the presented images. These recordings, however, have several drawbacks. For example, the resolution of the video recording may be insufficient to allow users to discern features in the projected images. In addition, portions of various ones of the presented images may be obscured by the person's body during his or her interactions with the images.
Rather than passively record a person's interactions with image-based media, other systems have been designed to interpret a person's interactions with images that are presented on a display. For example, some presentation systems include a camera that captures images of a person's interactions with the images that are presented on a display. The presentation system processes the captured images to determine the location of a particular object (e.g., a finger, a hand, or a pointing device) or to determine the intended meanings associated with particular movements, gestures, or configurations of the person's body. The results of these interpretations may be used to control the presentation on the display.